Insomnia is a prevalent health complaint which is often associated with functional impairments, reduced quality of life, and increased health-care costs. The specific aims of the proposed study are to (a) evaluate the short- and long-term effects of cognitive -behavior therapy (CBT), alone and in combination with medication, for chronic insomnia, (b) compare the efficacy of different maintenance strategies for combining drug and nondrug therapies to optimize long-term outcomes, and (c) examine the clinical impact of treatment on daytime functioning and psychological well-being. One hundred and fifty (150) adults meeting criteria for chronic insomnia will be randomly assigned to CBT or CBT plus medication. After the acute treatment phase, which will last eight weeks, patients will be entered into an extended treatment lasting six months. Of those treated with CBT alone initially, responders will be entered into an extended CBT or no treatment. Of those receiving the combined CBT plus medication (used on an as needed schedule) or CBT alone (plus medication tapering). Outcome will be evaluated across measures of sleep, clinical ratings, and several indices of daytime functioning. The measures will be administered at baseline, at the end of the acute and extended treatment phases, and at 6-, 12-, and 24-month follow-ups. The main research questions are: (a) Is CBT in conjunction with medication more effective than CBT alone for the acute treatment of insomnia? (b) When combining CBT and drug therapy, is it best to discontinue medication after the initial acute treatment or to continue using it on an intermittent (as needed) schedule in order to foster long-term maintenance of sleep improvements? and (c) What is the clinical impact of sleep improvement on daytime fatigue and performance, psychological symptoms, and quality of life? The public health significance of the proposed study is that it will provide useful information about optimal models for integrating behavioral and pharmacological therapies for the clinical management of insomnia.